Investigation of sensing performance of silicene nanoribbon towards methanol and ethanol molecules: A computational study

In this work, we perform an intricate computational analysis to investigate the adsorption mechanism of human breath exhaled VOCs, namely, methanol and ethanol, along with interfering water vapour on the surface of armchair silicene nanoribbon (ASiNR) by employing density functional theory to analyse the structural, electronic, and transport properties. The findings indicate that the most favorable adsorption configuration for methanol and ethanol involves the hydroxyl group (-OH) oriented towards the silicene surface, after optimisation. Moreover, we have calculated the adsorption energies which shows that ethanol is strongly physisorbed than methanol and water molecules on the ASiNR surface. Apart from that, the results of IV characteristics, transmission spectra and density of states corroborate these observations. In addition, we have computed the sensitivity (%), the results of which revealed that methanol demonstrates a high sensitivity of 42% compared to other molecules towards the surface of ASiNR. Furthermore, the recovery time of the sensor was found to be extremely long, which indicates that ASiNR based device has great potential for use as disposable sensors and scavengers for toxic gas molecules.